Frank dismissed Maresca's claims that Chelsea were the superior team on the day.
Frank said: “We are all slightly biased as coaches, and we definitely look at our side of the elephant. It’s probably difficult to look at the other side of the elephant — unless you are on top of it!
“I thought we had the better opportunities in the first half. I felt the second half was more even.”
The Dane added: “For me, maybe I am slightly biased, I saw five big chances to us. The (Yoane) Wissa header, the (Mikkel) Damsgaard chance, the Bryan (Mbeumo) shot on transition, the Keane (Lewis-Potter) header on a set piece, and of course Sepp’s (van den Berg) big header.
“So I think if there should have been a winner, it should have been us.
“But I thought it was an even game between two teams. I’m very happy with our performance against a top club who have spent a few quid on players over the last year or two.”